Assessing the impact of ultra‐sonication and thermo‐ultrasound on antioxidant indices and polyphenolic profile of apple‐grape juice blend

Abstract

Apple-grape juice blend (50:50) were subjected to blanching (thermal), high temperature-short time (72°C: 15 s), ultra-sonication (5 & 10 min), thermo-ultrasound (5 min, 40°C; 10 min, 40°C), and thermo-ultrasound (5 min, 50°C; 10 min, 50°C) and were compared to control treatment for the antioxidant indices. Furthermore, one best treatment each from ultra-sonication (10 min), thermo-ultrasound at 40°C (5 min), and thermoultrasound at 50°C (5 min) was analyzed through high performance liquid chromatography diode array detector (HPLC-DAD) for the quantification of individual phenolic acids, flavanols, stilbenes, and anthocyanins. Polyphenolic profile (HPLC-DAD) of apple-grape juice blends treated with ultra-sonicated (10 min), thermo-ultrasound (5 min; 40°C), and thermo-ultrasound (5 min: 50°C), resulted in identification of 23 polyphenols (9 phenolic acids; 6 flavanols; 1 stilbene; 7 anthocyanins). Results of HPLC characterization revealed a significant (p < .05) effect of tested treatments on all the polyphenols. Among phenolic acids, chlorogenic acid was observed to be highest (422.12 mg/L) in ultra-sonicated juice blend (T U-10 :10 min) followed by caftaric, gallic, syringic, vanillic, caffeic, ferulic, and cinnamic acids. While, content of resveratrol (stilbene), epigallocatechin gallate (flavanol), and Malvidin 3, 5-diglucoside (anthocyanin) were also found to be maximum (33.08, 386.32, and 70.25 mg/L, respectively) in ultra-sonicated (10 min) apple-grape juice blend samples. Keeping in view the polyphenolic profile and consumer preferences, ultra-sonication could be employed industrially as an alternative substitute of thermal processing techniques to enhance the quality of apple-grape juice blend.Practical application: For years, several nonthermal techniques are used for the preservation and quality improvement of fresh juices mainly by preventing the microorganisms and enzymes. Among these technique, single nonthermal treatment has a capacity to reduce the amount of microorganism and enzymes while a combined technique such as thermo-ultrasound has a better effect than single treatment, which have been investigated in this study. Therefore, this article would encourage the juice industrialists by applying these techniques for commercialization of juice and juice products in a more effectual manner.

Influence of ultrasound on selected microorganisms, chemical and structural changes in fresh tomato juice

“…Ultrasonic treatment of fruit juices had a minimal effect on the content of ascorbic acid and resulted in its better storage stability compared to thermal treatment 5 . Sonication also showed a significant increase in the antioxidant properties (DPPH and TAC) of the apple and grape juice blend compared to the control sample, blanching and high-temperature short-time pasteurization 2 . The combination of ultrasound with pulsed electric field resulted in an increase in the anti-radical activity of grape juice and a higher content of polyphenols, flavonoids, lycopene, anthocyanins and carotenoids 1 .…”

Study of continuous flow ultrasonication to improve total phenolic content and antioxidant activity in sorghum flour and its comparison with batch ultrasonication

“…In past few years, ultrasound assisted extraction of phenolic compounds from pomegranate peel [12] , mustard [13] , carrot pomace [14] , grape pomace [15] , beans [16] , buckwheat [17] , black soybean [18] , and orange pomace [19] has been extensively investigated but use of ultrasonication to enhance the phenolics itself in food is limited [20] , [21] , [22] and is few in case of sorghum [23] , [24] . The mechanism for ultrasonic is the cavitation of bubbles upon the propagation of the acoustic waves.…”

Thermosonication of tangerine juice: Effects on quality characteristics, bioactive compounds, and antioxidant activity

“…The US was recognized as a promising technology to meet the United States Food and Drug Administration (FDA) requirements to reduce the microbial counts 5 log CFU/g in fruit juices when used in combination with other technologies (Aadil et al., 2020; FDA, 2000; Tiwari, Muthukumarappan, O'Donnell, & Cullen, 2009; Zia, Khan, Zeng, Sehrish, & Aadil, 2019). Usually, the US has no effect in juice preservation when used at room temperature (≤25°C) (Zinoviadou et al., 2015), with good results when associated with heating in TS (Bermúdez‐Aguirre & Barbosa‐Cánovas, 2012; Valero et al., 2007).…”